RegisterSerumMarket: pass market_index explicitly

programs/mango-v4/src/instructions/register_serum_market.rs

@@ -18,7 +18,7 @@ pub struct RegisterSerumMarket<'info> {
 
     #[account(
         init,
-        // TODO: possibly use the market index instead of serum_market in the seed
+        // using the serum_market_external in the seed guards against registering the same market twice
         seeds = [group.key().as_ref(), b"SerumMarket".as_ref(), serum_market_external.key().as_ref()],
         bump,
         payer = payer,
@@ -35,17 +35,19 @@ pub struct RegisterSerumMarket<'info> {
 // TODO: should this be "configure_serum_market", which allows reconfiguring?
 pub fn register_serum_market(
     ctx: Context<RegisterSerumMarket>,
+    market_index: SerumMarketIndex,
     base_token_index: TokenIndex,
     quote_token_index: TokenIndex,
 ) -> Result<()> {
-    //let mut group = ctx.accounts.group.load_mut()?;
+    // TODO: must guard against accidentally using the same market_index twice!
+    // TODO: verify that base_token_index and quote_token_index are correct!
 
     let mut serum_market = ctx.accounts.serum_market.load_init()?;
     *serum_market = SerumMarket {
         group: ctx.accounts.group.key(),
         serum_program: ctx.accounts.serum_program.key(),
         serum_market_external: ctx.accounts.serum_market_external.key(),
-        market_index: 0, // TODO: likely globally tracked in the group?
+        market_index,
         base_token_index,
         quote_token_index,
         bump: *ctx.bumps.get("serum_market").ok_or(MangoError::SomeError)?,

programs/mango-v4/src/instructions/register_token.rs

@@ -23,6 +23,7 @@ pub struct RegisterToken<'info> {
 
     #[account(
         init,
+        // using the token_index in this seed guards against reusing it
         seeds = [group.key().as_ref(), b"Bank".as_ref(), &token_index.to_le_bytes()],
         bump,
         payer = payer,
@@ -42,6 +43,7 @@ pub struct RegisterToken<'info> {
 
     #[account(
         init,
+        // using the mint in this seed guards against registering the same mint twice
         seeds = [group.key().as_ref(), b"MintInfo".as_ref(), mint.key().as_ref()],
         bump,
         payer = payer,

programs/mango-v4/src/lib.rs

@@ -14,7 +14,7 @@ pub mod error;
 pub mod instructions;
 pub mod state;
 
-use state::TokenIndex;
+use state::{SerumMarketIndex, TokenIndex};
 
 declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
 
@@ -79,10 +79,11 @@ pub mod mango_v4 {
 
     pub fn register_serum_market(
         ctx: Context<RegisterSerumMarket>,
+        market_index: SerumMarketIndex,
         base_token_index: TokenIndex,
         quote_token_index: TokenIndex,
     ) -> Result<()> {
-        instructions::register_serum_market(ctx, base_token_index, quote_token_index)
+        instructions::register_serum_market(ctx, market_index, base_token_index, quote_token_index)
     }
 
     pub fn create_serum_open_orders(ctx: Context<CreateSerumOpenOrders>) -> Result<()> {

programs/mango-v4/tests/program_test/mango_client.rs

@@ -611,6 +611,7 @@ pub struct RegisterSerumMarketInstruction<'keypair> {
     pub serum_program: Pubkey,
     pub serum_market_external: Pubkey,
 
+    pub market_index: SerumMarketIndex,
     pub base_token_index: TokenIndex,
     pub quote_token_index: TokenIndex,
 }
@@ -624,6 +625,7 @@ impl<'keypair> ClientInstruction for RegisterSerumMarketInstruction<'keypair> {
     ) -> (Self::Accounts, instruction::Instruction) {
         let program_id = mango_v4::id();
         let instruction = Self::Instruction {
+            market_index: self.market_index,
             base_token_index: self.base_token_index,
             quote_token_index: self.quote_token_index,
         };

programs/mango-v4/tests/test_serum.rs

@@ -113,6 +113,7 @@ async fn test_serum() -> Result<(), TransportError> {
             admin,
             serum_program: context.serum.program_id,
             serum_market_external: serum_market_cookie.market,
+            market_index: 0,
             base_token_index,
             quote_token_index,
             payer,